1904.] Allen, Mammals from Santa Maria, Colombia. 417 



In addition to the 23 new forms enumerated above, three 

 others will be found described in the present paper, 

 while 10 have been described by Mr. Bangs and i by Mr. G. 

 H. Miller, Jr., or 37 in all, out of a total of 86 species recorded 

 from the Santa Marta region. It is probable that still others 

 will require new names, since several of the species of Ory- 

 zomys recorded by Mr. Bangs from the Sierra Nevada de 

 Santa Marta as identical with Merida or Bogota species can 

 hardly be the same, although perhaps representative of them, 

 since continuous distribution is, to say the least, improbable. 



As already said in my report on the birds of this region 

 (this Bulletin, XIII, 1900, p. 122), the fauna of the Santa 

 Marta district (including the high Sierra and low-coast region) 

 presents many peculiar forms, a few of them strongly differ- 

 entiated from their nearest allies in neighboring regions, 

 others their less modified representatives. This is as would 

 be expected from its topographically isolated position, being, 

 as Mr. Smith has expressed it, "semi-insular" in respect to its 

 physical conditions, and has doubtless been long separated, 

 as regards its mountainous areas, from the Andean ranges to 

 the westward and southward. Also, as already said in another 

 connection, "the home of many 'Colombia* species is to be 

 looked for elsewhere than eastern Colombia," as illustrated by 

 the case of Geoffrey's Sciurus variabilis, discussed later in the 

 present paper. 



ANNOTATED LIST. 



i. Marmosa mitis Bangs. Fifteen specimens, as follows: 

 Bonda, 2 adult males, March and August; 4 females and 6 

 young, Aug. 8-Sept. 4; Mamatoco, i adult female, June i; 

 Taganga, i adult female, June 25; Minca, i adult male, June. 



"OPOSSUM RAT. A small grayish-brown species, found in 

 the forest from sea-level to 4000 feet or higher. It is arboreal 

 and strictly nocturnal, passing the day in hollow trees. The 

 females have about eight young, which, when partly grown, 

 are carried on her back, their prehensile tails twining about 

 the mother's tail as she holds it arched over her body. Opos- 

 sum rats appear to live mainly on insects and birds' eggs ; 

 they prowl about on the branches at night. I once caught 

 November, 1904.] 2? 



